DOI: 10.5194/tc-11-2439-2017
Scopus记录号: 2-s2.0-85032966184
论文题名: Methanesulfonic acid (MSA) migration in polar ice: Data synthesis and theory
作者: Osman M ; , Das S ; B ; , Marchal O ; , Evans M ; J
刊名: Cryosphere
ISSN: 19940416
出版年: 2017
卷: 11, 期: 6 起始页码: 2439
结束页码: 2462
语种: 英语
英文关键词: atmospheric transport
; climate signal
; ice core
; paleoclimate
; primary production
; sea ice
; snow accumulation
; Antarctica
; Arctic
; Greenland
英文摘要: Methanesulfonic acid (MSA; CH3SO3H) in polar ice is a unique proxy of marine primary productivity, synoptic atmospheric transport, and regional sea-ice behavior. However, MSA can be mobile within the firn and ice matrix, a post-depositional process that is well known but poorly understood and documented, leading to uncertainties in the integrity of the MSA paleoclimatic signal. Here, we use a compilation of 22 ice core MSA records from Greenland and Antarctica and a model of soluble impurity transport in order to comprehensively investigate the vertical migration of MSA from summer layers, where MSA is originally deposited, to adjacent winter layers in polar ice. We find that the shallowest depth of MSA migration in our compilation varies over a wide range (∼2 to 400 m) and is positively correlated with snow accumulation rate and negatively correlated with ice concentration of NaC (typically the most abundant marine cation). Although the considered soluble impurity transport model provides a useful mechanistic framework for studying MSA migration, it remains limited by inadequate constraints on key physicochemical parameters-most notably, the diffusion coefficient of MSA in cold ice (DMS). We derive a simplified version of the model, which includes DMS as the sole parameter, in order to illuminate aspects of the migration process. Using this model, we show that the progressive phase alignment of MSA and NaC concentration peaks observed along a high-resolution West Antarctic core is most consistent with 10-12 m2 s-1 DMS 10-11 m-2 s-1, which is 1 order of magnitude greater than the DMS values previously estimated from laboratory studies. More generally, our data synthesis and model results suggest that (i) MSA migration may be fairly ubiquitous, particularly at coastal and (or) highaccumulation regions across Greenland and Antarctica; and (ii) can significantly change annual and multiyear MSA concentration averages. Thus, in most cases, caution should be exercised when interpreting polar ice core MSA records, although records that have undergone severe migration could still be useful for inferring decadal and lower-frequency climate variability. © 2017 Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75485
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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作者单位: Massachusetts Institute of Technology, Woods Hole Oceanographic Institution Joint Program in Oceanography, Applied Ocean Sciences and Engineering, Woods Hole, MA, United States; Dept. of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, United States; Dept. of Chemistry, Wheaton College, Wheaton, MA, United States
Recommended Citation:
Osman M,, Das S,B,et al. Methanesulfonic acid (MSA) migration in polar ice: Data synthesis and theory[J]. Cryosphere,2017-01-01,11(6)